冷原子的双阱微磁表面囚禁  

Double-Well Magnetic Surface Microtraps for Cold Atoms

作　　者：胡建军[1] 印建平[2] 

机构地区：[1]苏州大学现代光学技术研究所,苏州215006 [2]华东师范大学物理系,波谱与光谱学教育部重点实验室,上海200062

出　　处：《光学学报》2003年第7期769-776,共8页Acta Optica Sinica

基　　金：国家自然科学基金 (698780 1 9;1 0 1 740 50 );江苏省教育厅自然科学重点基金 (00KJB1 4 0 0 0 1 );江苏省高校青蓝工程新世纪学术带头人培养基金;上海市重点学科和教育部 2 1 1工程专项基金资助课题

摘　　要：提出了两种新颖的采用载流导线的双阱微磁表面囚禁方案 (即双U形与双Z形导线囚禁 )。通过改变囚禁方案中直导线中的电流方向 ,即可将双U形导线囚禁改变为双Z形导线囚禁 ;如果逐渐减小直导线中的电流大小 ,即可将一个双阱微磁囚禁连续地合并为一个单阱微磁囚禁 ,反之亦然。详细计算和分析了上述两种载流导线囚禁方案的磁场及其梯度的空间分布。研究发现在导线中通以较小的电流 ,即可在导线表面附近产生很大的磁场梯度及其曲率。例如当电流为 0 .2A时 ,其磁场梯度和曲率可分别达到 0 .2T/cm和 1 0T/cm2 以上。由于双U形导线囚禁中存在磁场零点 ,而双Z形导线囚禁中仅存在磁场最小值 ,所以双U形导线囚禁仅适用于制备双样品磁光囚禁 (MOT)或研究中性原子的冷碰撞 ,而双Z形导线囚禁除了可用于研究原子的冷碰撞之外 ,还可以用于制备双样品玻色爱因斯坦凝聚 (BEC)Two novel schemes are proposed to form double well magnetic surface microtraps for cold atoms using double U shaped or double Z shaped current carrying wires. By changing the direction of current in a straight wire, a double U shaped wire trap will be changed into a double Z shaped wire trap. This study shows that the two double well magnetic microtraps can be continuously changed into a single well one by reducing the current in the straight wire from a suitable value into zero, and vice versa. The spatial distributions of magnetic fields from double U shaped and double Z shaped current\|carrying wires layouts and their gradients and curvatures are calculated and analyzed. It is found that the maximum magnetic field gradient greater than 0.2 T/cm and the maximum field curvature (at each trap center) greater than 10 T/cm 2 can be generated in our double well magnetic surface microtraps as I 1=I 2=0.2 A. Since there is a point of zero magnetic field at each trap center in the double U shaped wire trap with two magnetic microwells, whereas there is no any point of zero magnetic field in the double Z shaped wire trap with two microwells, the double U shaped wire trap is only used to realize two species MOT and to study cold collisions from two atomic samples and so on. The double Z shaped wire trap cannot only be used to study the collisions of cold atoms, but also to realize and study two species BEC or experimentally study the properties of double well BEC and so on.

关 键 词：冷原子 双阱微磁表面囚禁 载流导线 原子囚禁 双样品玻色-爱因斯坦凝聚 冷碰撞 双样品磁光囚禁 

分 类 号：O413[理学—理论物理] O562[理学—物理]